CN105754485A discloses the deep processing of rosin and discloses a rosin glycerin ester production method, for rosin glycerin ester with high softening point and high purity. CN105778765A discloses a method for producing a pentaerythritol rosin ester with high softening point and purity. CN105802500A and CN105802501A disclose methods for producing rosin glycerin ester that is high in purity and light in color. JP02064182 discloses a rosin ester having light color and excellent thermal stability, wherein the esterification reaction is performed by the dehydrative condensation of the rosin and the alcohol in an inert gas stream. Holton, H. H., Prepr. Pap. Annu. Meet. Tech. Sect., C.P.P.A, 62nd, CPPA, Montreal, QC, Canada, 1976, p. A107 discloses the use of anthraquinone as a pulping catalyst in paper industry.
There remains an unmet need for improving the color properties of rosin esters for various applications.